A novel and convenient oxidative radical cyclization of N-substituted N-arylacrylamides for the synthesis of 3-thiocyanated oxindoles has been developed by using AgSCN and K2S2O8 as the radical source. This process allows a consistent and convenient access to SCN-containing heterocycles bearing a broad range of functional groups in good to excellent yields (up to 91%). Moreover, the use of inexpensive
Silver-Mediated Radical Trifluoromethylarylation of Activated Alkenes for the Synthesis of Oxindoles Bearing a CF3 Group
作者:Fu-Xue Chen、Yao-Feng Wang、Jiashen Qiu、Dejie Kong
DOI:10.1055/s-0033-1341272
日期:——
A radical trifluoromethylarylation of N-arylacrylamides with in situ generated [AgCF3] species from Me3SiCF3 and AgF in DMF is established through a tandem radical addition and C-H activation pathway. It provided a concise method to prepare 21 examples of CF3-containing oxindoles within four hours.
Rotational features of carbon-nitrogen bonds in axially chiral o-tert-butyl anilides and related molecules. Potential substrates for the ‘prochiral auxiliary’ approach to asymmetric synthesis
作者:Dennis P. Curran、Gregory R. Hale、Steven J. Geib、Aaron Balog、Quezia B. Cass、Ana Luiza G. Degani、Marcelo Z. Hernandes、Luiz Carlos G. Freitas
DOI:10.1016/s0957-4166(97)00599-5
日期:1997.12
A new strategy for asymmetric induction termed the 'prochiral auxiliary' approach is introduced. Reactions of acylating agents with prochiral N-methyl-o-tert-butyl aniline provide anilides that are axially chiral by virtue of restricted rotation about the N-Ar bond, Rotamer populations about the amide bond (E/Z) were studied by H-1 NMR. Several pairs of enantiomeric o-tert-butyl anilides were separated by chiral chromatography and barriers about the N-Ar bond were measured by thermal racemization. Related o-(1-(trialkylsilyloxy)-1-methylethyl) anilides were also studied. (C) 1997 Published by Elsevier Science Ltd. All rights reserved.
Visible-Light-Induced, Catalyst-Free Monofluoromethyl Sulfonylation of Alkenes with Iodine(III) Reagent and DABSO